Source file hlt_elim.ml
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open Logtk
open Libzipperposition
module T = Term
module Ty = Type
module Lits = Literals
module Lit = Literal
module A = Libzipperposition_avatar
let section = Util.Section.make ~parent:Const.section "hlt-elim"
let k_enabled = Flex_state.create_key ()
let k_max_depth = Flex_state.create_key ()
let k_simpl_new = Flex_state.create_key ()
let k_clauses_to_track = Flex_state.create_key ()
let k_max_self_impls = Flex_state.create_key ()
let k_unit_propagated_hle = Flex_state.create_key ()
let k_unit_htr = Flex_state.create_key ()
let k_hte = Flex_state.create_key ()
let k_hle = Flex_state.create_key ()
let k_max_tracked_clauses = Flex_state.create_key ()
let k_track_eq = Flex_state.create_key ()
let k_insert_only_ordered = Flex_state.create_key ()
module type S = sig
module Env : Env.S
module C : module type of Env.C
(** {5 Registration} *)
val setup : unit -> unit
end
module Make(E : Env.S) : S with module Env = E = struct
module Env = E
module C = Env.C
module CS = C.ClauseSet
module L = Literal
module PremiseIdx = NPDtree.MakeTerm(struct
type t = (CS.t T.Tbl.t) * (CS.t option)
let compare (a1,_) (a2,_) = compare (T.Tbl.length a1) (T.Tbl.length a2)
end)
module ConclusionIdx = NPDtree.MakeTerm(struct
type t = T.t
let compare = Term.compare
end)
module UnitIdx = NPDtree.MakeTerm(struct
type t = C.t
let compare = C.compare
end)
let prems_ = ref (PremiseIdx.empty ())
let concls_ = ref (ConclusionIdx.empty ())
let units_ = ref (UnitIdx.empty ())
let cl_occs = ref Util.Int_map.empty
let tracked_cls = ref 0
let [@inline] tracking_eq () =
Env.flex_get k_track_eq
let idx_sc, q_sc = 0, 1
let retrieve_idx ~getter (premise, q_sc) =
match T.view premise with
| T.AppBuiltin(Builtin.Eq, ([_;a;b]|[a;b])) when tracking_eq () ->
Iter.append (getter (premise, q_sc)) (getter ((T.Form.eq b a), q_sc))
| T.AppBuiltin(Builtin.Neq, ([_;a;b]|[a;b])) when tracking_eq () ->
Iter.append (getter (premise, q_sc)) (getter ((T.Form.neq b a), q_sc))
| _ -> getter (premise, q_sc)
let retrieve_gen_prem_idx () =
retrieve_idx ~getter:(PremiseIdx.retrieve_generalizations (!prems_, idx_sc))
let retrieve_spec_prem_idx () =
retrieve_idx ~getter:(PremiseIdx.retrieve_specializations (!prems_, idx_sc))
let retrieve_gen_concl_idx () =
retrieve_idx ~getter:(ConclusionIdx.retrieve_generalizations (!concls_,idx_sc))
let retrieve_spec_concl_idx () =
retrieve_idx ~getter:(ConclusionIdx.retrieve_specializations (!concls_,idx_sc))
let retrieve_gen_unit_idx unit_sc =
retrieve_idx ~getter:(UnitIdx.retrieve_generalizations (!units_, unit_sc))
let [@inline] get_predicate lit =
match lit with
| L.Equation(lhs,_,_) when L.is_predicate_lit lit ->
Some (lhs, Lit.is_pos lit)
| L.Equation(lhs,rhs,sign) when tracking_eq () ->
Some (T.Form.eq lhs rhs, sign)
| _ -> None
let [@inline] matching_eq ~subst ~pattern (t, sc) =
try
Unif.FO.matching ~subst ~pattern (t, sc)
with Unif.Fail ->
match T.view t with
| T.AppBuiltin(Builtin.Eq, ([_;a;b]|[a;b])) when tracking_eq () ->
Unif.FO.matching ~subst ~pattern (T.Form.eq b a, sc)
| T.AppBuiltin(Builtin.Neq, ([_;a;b]|[a;b])) when tracking_eq () ->
Unif.FO.matching ~subst ~pattern (T.Form.neq b a, sc)
| _ -> raise Unif.Fail
let [@inline] flip_eq t =
match T.view t with
| T.AppBuiltin(Builtin.Eq, ([a;b]|[_;a;b])) when tracking_eq () ->
T.Form.eq b a
| T.AppBuiltin(Builtin.Neq, ([a;b]|[_;a;b])) when tracking_eq () ->
T.Form.neq b a
| _ -> t
let [@inline] cl_is_ht_trackable cl =
Trail.is_empty (C.trail cl) &&
(match C.lits cl with
| [| l1; l2 |] ->
CCOpt.is_some (get_predicate l1) && CCOpt.is_some (get_predicate l2)
| _ -> false)
let [@inline] rec normalize_negations lhs =
match T.view lhs with
| T.AppBuiltin(Builtin.Not, [t]) ->
(match T.view t with
| T.AppBuiltin(Builtin.Not, [s]) ->
normalize_negations s
| T.AppBuiltin(Builtin.Eq, ([_;a;b]|[a;b])) ->
T.Form.neq a b
| T.AppBuiltin(Builtin.Neq, ([_;a;b]|[a;b])) ->
T.Form.eq a b
| _ -> lhs)
| _ -> lhs
let [@inline] lit_to_term ?(negate=false) a_lhs sign =
let sign = if negate then not sign else sign in
normalize_negations (if sign then a_lhs else T.Form.not_ a_lhs)
let register_cl_term cl premise =
let premise_set =
Term.Set.add premise
(Util.Int_map.get_or ~default:Term.Set.empty (C.id cl) !cl_occs) in
cl_occs := Util.Int_map.add (C.id cl) premise_set !cl_occs
let generalization_present premise concl =
retrieve_gen_prem_idx () (premise, q_sc)
|> Iter.exists (fun (_, (tbl, _), subst) ->
T.Tbl.keys tbl
|> Iter.exists (fun t ->
try
ignore(matching_eq ~subst ~pattern:(t, idx_sc) (concl, q_sc));
true
with Unif.Fail -> false))
let remove_instances premise concl =
retrieve_spec_prem_idx () (premise, q_sc)
|> (fun i -> Iter.fold (fun tasks (t, (tbl, _), subst) ->
let sets_to_remove =
Iter.fold (fun acc (s,cls) ->
try
let subst = matching_eq ~subst ~pattern:(concl,q_sc) (s,idx_sc) in
if Subst.is_renaming subst then acc else cls :: acc
with Unif.Fail -> acc
) [] (T.Tbl.to_iter tbl) in
(t, sets_to_remove) :: tasks
) [] i)
|> CCList.iter (fun (t, sets) ->
prems_ := PremiseIdx.update_leaf !prems_ t (fun (tbl, _) ->
T.Tbl.filter_map_inplace (fun concl proofset ->
concls_ := ConclusionIdx.remove !concls_ concl t;
if List.exists (fun set -> CS.subset set proofset) sets then None
else Some proofset) tbl;
T.Tbl.length tbl == 0
);
)
let compute_is_unit tbl concl cl =
if Env.flex_get k_unit_htr then (
let neg_concl = normalize_negations (T.Form.not_ concl) in
let neg_concl_flip = normalize_negations (T.Form.not_ (flip_eq concl)) in
T.Tbl.find_opt tbl neg_concl
|> CCOpt.(<+>) (T.Tbl.find_opt tbl neg_concl_flip)
|> CCOpt.(<$>) (CS.add cl)
) else None
let add_transitive_conclusions premise concl cl =
Util.debugf ~section 3 "transitive conclusion: @[%a@] --> @[%a@]"
(fun k -> k T.pp premise T.pp concl);
retrieve_spec_concl_idx () (premise,q_sc)
|> Iter.iter (fun (concl',premise',subst) ->
Util.debugf ~section 3 "found: @[%a@] --> @[%a@]"
(fun k -> k T.pp premise' T.pp concl');
let became_unit = ref None in
prems_ := PremiseIdx.update_leaf !prems_ premise' (fun (tbl, is_unit) ->
(match T.Tbl.get tbl concl' with
| Some old_proofset ->
if CS.cardinal old_proofset < Env.flex_get k_max_depth then (
let proofset = CS.add cl old_proofset in
register_cl_term cl premise';
let concl = (Subst.FO.apply Subst.Renaming.none subst (concl, q_sc)) in
concls_ := ConclusionIdx.add !concls_ concl premise';
T.Tbl.add tbl concl proofset;
if CCOpt.is_none is_unit then (
match compute_is_unit tbl concl cl with
| Some proofset -> became_unit := Some(proofset,tbl)
| None -> ()
)
)
| None -> assert false;);
CCOpt.is_none !became_unit
);
(match !became_unit with
| Some (ps, tbl) ->
ignore(PremiseIdx.update_leaf !prems_ premise' (fun (tbl, is_unit) -> assert false));
prems_ := PremiseIdx.add !prems_ premise' (tbl, Some ps)
| _ -> ());
)
let triggered_conclusions tbl premise' concl cl =
let aux concl =
T.Tbl.add tbl concl (CS.singleton cl);
concls_ := ConclusionIdx.add !concls_ concl premise';
register_cl_term cl premise';
let max_proof_size = Env.flex_get k_max_depth in
retrieve_gen_prem_idx () (concl, q_sc)
|> Iter.iter (fun (_,(tbl', _),subst) ->
T.Tbl.to_iter tbl'
|> Iter.iter (fun (t,proof_set) ->
if C.ClauseSet.cardinal proof_set < max_proof_size then (
let new_cls = CS.add cl proof_set in
CS.iter (fun cl -> register_cl_term cl premise') new_cls;
let concl = (Subst.FO.apply Subst.Renaming.none subst (t, idx_sc)) in
concls_ := ConclusionIdx.add !concls_ concl premise';
T.Tbl.add tbl concl (new_cls)
))
) in
try
let subst = Unif.FO.matching ~pattern:(premise',0) (concl,1) in
let i = ref 0 in
let concl' = Subst.FO.apply Subst.Renaming.none subst (concl,0) in
if T.equal concl concl' then raise Unif.Fail;
let concl = ref concl in
while !i <= Env.flex_get k_max_self_impls do
aux !concl;
concl := Subst.FO.apply Subst.Renaming.none subst (!concl,0);
if T.depth !concl > 3 then (
i := Env.flex_get k_max_self_impls + 1
);
i := !i + 1;
done;
with Unif.Fail ->
aux concl
let get_unit_predicate cl =
if Trail.is_empty (C.trail cl) then (
match C.lits cl with
| [| (L.Equation(lhs, _, _) as l) |] when L.is_predicate_lit l ->
Some (lit_to_term lhs (L.is_pos l))
| [| L.Equation(lhs, rhs, sign) |] when tracking_eq () ->
Some (lit_to_term (T.Form.eq lhs rhs) (sign))
| _ -> None)
else None
let add_new_premise premise concl cl =
let alpha_renaming =
retrieve_spec_prem_idx () (premise, q_sc)
|> Iter.find (fun (premise', tbl, subst) ->
if Subst.is_renaming subst then Some (premise', subst)
else None
) in
match alpha_renaming with
| Some (premise', subst) ->
let concl = Subst.FO.apply Subst.Renaming.none subst (concl, q_sc) in
let tbl_ = ref (T.Tbl.create 0) in
let became_unit = ref None in
prems_ := PremiseIdx.update_leaf !prems_ premise' (fun (tbl,is_unit) ->
if not (T.Tbl.mem tbl concl) && not (T.Tbl.mem tbl (flip_eq concl)) then (
triggered_conclusions tbl premise' concl cl;
if CCOpt.is_none is_unit then (
(match compute_is_unit !tbl_ concl cl with
| Some ps -> became_unit := Some (ps, tbl)
| None -> ());
)
);
CCOpt.is_none !became_unit
);
(match !became_unit with
| Some (ps,tbl) ->
ignore(PremiseIdx.update_leaf !prems_ premise' (fun (tbl, is_unit) -> assert false));
prems_ := PremiseIdx.add !prems_ premise (tbl,Some ps)
| None -> ())
| _ ->
let tbl = T.Tbl.create 64 in
triggered_conclusions tbl premise concl cl;
prems_ := PremiseIdx.add !prems_ premise (tbl,compute_is_unit tbl concl cl)
let insert_implication premise concl cl =
if not (generalization_present premise concl) &&
not (T.equal premise concl) &&
not (T.equal premise (flip_eq concl)) then (
remove_instances premise concl;
add_transitive_conclusions premise concl cl;
add_new_premise premise concl cl;
)
let insert_into_indices cl =
match CCArray.map get_predicate (C.lits cl) with
| [| Some (a_lhs, a_sign); Some (b_lhs, b_sign) |] ->
let elig =
if Env.flex_get k_insert_only_ordered
then C.eligible_param (cl,0) Subst.empty
else CCBV.create ~size:2 true in
if (CCBV.get elig 0) then (
insert_implication (lit_to_term ~negate:true a_lhs a_sign)
(lit_to_term b_lhs b_sign) cl);
if (CCBV.get elig 1) then (
insert_implication (lit_to_term ~negate:true b_lhs b_sign)
(lit_to_term a_lhs a_sign) cl)
| _ -> ()
let limit_not_reached () =
let tracked = !tracked_cls in
let tracked_max = Env.flex_get k_max_tracked_clauses in
tracked_max == -1 || tracked <= tracked_max
let track_clause cl =
if cl_is_ht_trackable cl && limit_not_reached () then (
Util.debugf ~section 3 "tracking @[%a@]" (fun k -> k C.pp cl);
insert_into_indices cl;
incr tracked_cls;
Util.debugf ~section 2 "idx_size: @[%d@]" (fun k -> k (PremiseIdx.size !prems_));
Util.debugf ~section 3 "premises:" CCFun.id;
PremiseIdx.iter !prems_ (fun t (tbl,_) ->
Util.debugf ~section 3 "@[%a@] --> @[%a@]" (fun k -> k T.pp t (Iter.pp_seq T.pp) (T.Tbl.keys tbl))
);
) else if Env.flex_get k_unit_propagated_hle then (
match get_unit_predicate cl with
| Some unit ->
units_ := UnitIdx.add !units_ unit cl
| None -> ()
)
let find_implication cl premise concl =
retrieve_gen_prem_idx () (premise, q_sc)
|> Iter.find (fun (premise', (tbl,_), subst) ->
T.Tbl.to_iter tbl
|> Iter.find (fun (concl', proofset) ->
try
if CS.mem cl proofset then None
else (
let subst = matching_eq ~subst ~pattern:(concl', idx_sc) (concl, q_sc) in
Some(premise', concl', proofset, subst))
with Unif.Fail -> None))
let do_propagated_simpl cl =
let bv = CCBV.create ~size:( C.length cl ) true in
let proofset = ref (CS.empty) in
let exception PropagatedHTE of T.t * CS.t in
let is_unit = C.length cl == 1 in
try
CCArray.iteri (fun i lit ->
match get_predicate lit with
| Some (lhs, sign) ->
let lhs_neg = lit_to_term ~negate:true lhs sign in
let lhs = lit_to_term lhs sign in
let unit_sc = (max idx_sc q_sc) + 1 in
let (<+>) = CCOpt.(<+>) in
if is_unit then ()
else (
CCOpt.get_or ~default:()
(
retrieve_gen_concl_idx () (lhs, q_sc)
|> Iter.find_map (fun (concl, premise, subst) ->
let orig_premise = premise in
let premise = Subst.FO.apply Subst.Renaming.none subst (premise, idx_sc) in
retrieve_gen_unit_idx unit_sc (premise, idx_sc)
|> Iter.head
|> CCOpt.map (fun (_, unit_cl, _) ->
prems_ := PremiseIdx.update_leaf !prems_ orig_premise (fun (tbl,_) ->
let proofset' = CS.add unit_cl (T.Tbl.find tbl concl) in
if not (CS.mem cl proofset') then (
raise (PropagatedHTE(lhs, proofset'));
);
true
);
))
<+> (
retrieve_gen_prem_idx () (lhs_neg, q_sc)
|> Iter.find_map ( fun (premise, (tbl, _), subst) ->
T.Tbl.to_iter tbl
|> Iter.find_map (fun (concl, ps) ->
let concl = Subst.FO.apply Subst.Renaming.none subst (concl, idx_sc) in
let neg_concl = normalize_negations (T.Form.not_ concl) in
let unit_sc = (max idx_sc q_sc) + 1 in
retrieve_gen_unit_idx unit_sc (neg_concl, idx_sc)
|> Iter.head
|> CCOpt.map (fun (_, unit_cl, _) ->
let proofset' = CS.add unit_cl ps in
if not (CS.mem cl proofset') then (
raise (PropagatedHTE(lhs, proofset'));
)))))));
CCOpt.get_or ~default:()
(
retrieve_gen_concl_idx () (lhs_neg, q_sc)
|> Iter.find_map (fun (concl, premise, subst) ->
let orig_premise = premise in
let premise = Subst.FO.apply Subst.Renaming.none subst (premise, idx_sc) in
retrieve_gen_unit_idx unit_sc (premise, idx_sc)
|> Iter.head
|> CCOpt.map (fun (_, unit_cl, _) ->
prems_ := PremiseIdx.update_leaf !prems_ orig_premise (fun (tbl,_) ->
let proofset' = T.Tbl.find tbl concl in
if not (CS.mem cl proofset') then (
proofset := CS.union (CS.add unit_cl (proofset')) !proofset;
CCBV.reset bv i);
true
);
))
<+> (
retrieve_gen_prem_idx () (lhs, q_sc)
|> Iter.find_map ( fun (_, (tbl, _), subst) ->
T.Tbl.to_iter tbl
|> Iter.find_map (fun (concl, ps) ->
let concl = Subst.FO.apply Subst.Renaming.none subst (concl, idx_sc) in
let neg_concl = normalize_negations (T.Form.not_ concl) in
let unit_sc = (max idx_sc q_sc) + 1 in
retrieve_gen_unit_idx unit_sc (neg_concl, idx_sc)
|> Iter.head
|> CCOpt.map (fun (_, unit_cl, _) ->
let proofset' = CS.add unit_cl ps in
if not (CS.mem cl proofset') then (
proofset := CS.union proofset' !proofset;
CCBV.reset bv i
))))))
| None -> ()
) (C.lits cl);
if CCBV.is_empty (CCBV.negate bv) then None
else (
let lit_l = List.rev (CCBV.select bv (C.lits cl)) in
let proof =
Proof.Step.simp ~rule:(Proof.Rule.mk "propagated_hle")
(List.map C.proof_parent (cl :: CS.to_list !proofset))
in
Some (C.create ~penalty:(C.penalty cl) ~trail:(C.trail cl) lit_l proof)
)
with PropagatedHTE(lit_t, proofset) ->
let lit_l = [L.mk_prop lit_t true] in
let proof =
Proof.Step.simp ~rule:(Proof.Rule.mk "propagated_htr")
(List.map C.proof_parent (cl :: CS.to_list proofset))
in
let repl = C.create ~penalty:(C.penalty cl) ~trail:(C.trail cl) lit_l proof in
let tauto = C.create ~penalty:(C.penalty cl) ~trail:(C.trail cl) [L.mk_tauto] proof in
Util.debugf ~section 1 "simplified[unit_htr(%a)]: @[@[%a@] --> @[%a@]@]@. using @[%a@]"
(fun k -> k T.pp lit_t C.pp cl C.pp repl (CS.pp C.pp) proofset);
E.add_passive (Iter.singleton repl);
Some (tauto)
let unit_simplify cl =
let exception UnitHTR of T.t * CS.t in
let n = C.length cl in
let bv = CCBV.create ~size:n true in
let proofset = ref CS.empty in
try
CCArray.iteri (fun i i_lit ->
match get_predicate i_lit with
| Some(i_lhs, i_sign) ->
let i_t = lit_to_term (i_lhs) (i_sign) in
let i_neg_t = lit_to_term ~negate:true (i_lhs) (i_sign) in
let unit_htr () =
retrieve_gen_prem_idx () (i_neg_t, q_sc)
|> Iter.find_map (fun (_, (_,is_unit), subst) ->
if Subst.is_renaming subst then None else is_unit)
in
let unit_hle () =
retrieve_gen_prem_idx () (i_t, q_sc)
|> Iter.find_map (fun (_, (_,is_unit), _) -> is_unit)
in
(match unit_htr () with
| Some cs -> raise (UnitHTR(i_t, cs))
| None -> (
match unit_hle () with
| Some cs ->
CCBV.reset bv i;
proofset := CS.union cs !proofset
| None -> ()
))
| None -> ()
) (C.lits cl);
if CCBV.is_empty (CCBV.negate bv) then None
else (
let lit_l = List.rev @@ CCBV.select bv (C.lits cl) in
let proof =
Proof.Step.simp ~rule:(Proof.Rule.mk "unit_hle")
(List.map C.proof_parent (cl :: CS.to_list !proofset))
in
let res = C.create ~penalty:(C.penalty cl) ~trail:(C.trail cl) lit_l proof in
Util.debugf ~section 1 "simplified[hle]: @[%a@] --> @[%a@]"
(fun k -> k C.pp cl C.pp res);
Util.debugf ~section 1 "used: @[%a@]" (fun k -> k (CS.pp C.pp) !proofset);
Some (res))
with UnitHTR(lit_t, proofset) ->
let lit_l = [L.mk_prop lit_t true] in
let proof =
Proof.Step.simp ~rule:(Proof.Rule.mk "unit_htr")
(List.map C.proof_parent (cl :: CS.to_list proofset))
in
let repl = C.create ~penalty:(C.penalty cl) ~trail:(C.trail cl) lit_l proof in
let tauto = C.create ~penalty:(C.penalty cl) ~trail:(C.trail cl) [L.mk_tauto] proof in
Util.debugf ~section 1 "simplified[unit_htr(%a)]: @[@[%a@] --> @[%a@]@]"
(fun k -> k T.pp lit_t C.pp cl C.pp repl);
E.add_passive (Iter.singleton repl);
Some (tauto)
let do_hte_hle cl =
let exception HiddenTauto of T.t * T.t * CS.t in
let n = C.length cl in
if n >= 2 then (
try
let bv = CCBV.create ~size:n true in
let proofset = ref CS.empty in
CCArray.iteri (fun i i_lit ->
match get_predicate i_lit with
| Some(i_lhs, i_sign) when CCBV.get bv i ->
let i_t = lit_to_term (i_lhs) (i_sign) in
let i_neg_t = lit_to_term ~negate:true (i_lhs) (i_sign) in
CCArray.iteri (fun j j_lit ->
begin match get_predicate j_lit with
| Some (j_lhs, j_sign) when CCBV.get bv j && i!=j ->
let j_t = lit_to_term (j_lhs) (j_sign) in
let j_neg_t = lit_to_term ~negate:true (j_lhs) (j_sign) in
if Env.flex_get k_hte then (
(match find_implication cl i_neg_t j_t with
| Some (lit_a, lit_b, proofset, subst)
when (C.length cl != 2 || not (Subst.is_renaming subst)) ->
raise (HiddenTauto (lit_a, lit_b, proofset))
| _ -> ())
);
if Env.flex_get k_hle then (
let (<+>) = CCOpt.(<+>) in
(match find_implication cl i_neg_t j_neg_t
<+> find_implication cl j_t i_t with
| Some (_, _, proofset',subst) ->
CCBV.reset bv j;
Util.debugf ~section 3 "@[%a@] --> @[%a@]"
(fun k -> k T.pp i_neg_t T.pp j_neg_t);
Util.debugf ~section 3 "used(%d): @[%a@]"
(fun k -> k j (CS.pp C.pp) proofset');
proofset := CS.union proofset' !proofset
| _ -> () )
)
| _ -> () end
) (C.lits cl)
| _ -> ()
) (C.lits cl);
if CCBV.is_empty (CCBV.negate bv) then None
else (
let lit_l = List.rev @@ CCBV.select bv (C.lits cl) in
let proof =
Proof.Step.simp ~rule:(Proof.Rule.mk "hidden_literal_elimination")
(List.map C.proof_parent (cl :: CS.to_list !proofset))
in
let res = C.create ~penalty:(C.penalty cl) ~trail:(C.trail cl) lit_l proof in
Util.debugf ~section 1 "simplified[hle]: @[%a@] --> @[%a@]"
(fun k -> k C.pp cl C.pp res);
Util.debugf ~section 1 "used: @[%a@]" (fun k -> k (CS.pp C.pp) !proofset);
Some (res))
with HiddenTauto(lit_a,lit_b,proofset) ->
let lit_l = [L.mk_prop lit_a false; L.mk_prop lit_b true] in
let proof =
Proof.Step.simp ~rule:(Proof.Rule.mk "hidden_tautology_elimination")
(List.map C.proof_parent (cl :: CS.to_list proofset))
in
let tauto = C.create ~penalty:(C.penalty cl) ~trail:(C.trail cl) [L.mk_tauto] proof in
let repl = C.create ~penalty:(C.penalty cl + (if CS.cardinal proofset != 1 then 0 else 1)) ~trail:(C.trail cl) lit_l proof in
E.add_passive (Iter.singleton repl);
Util.debugf ~section 1 "simplified[hte]: @[@[%a@] --> @[%a@]@]" (fun k -> k C.pp cl C.pp repl);
Util.debugf ~section 1 "used @[%a@] --> @[%a@] @[(%a)@]" (fun k -> k T.pp lit_a T.pp lit_b (CS.pp C.pp) proofset);
Some (tauto)
) else None
let simplify_opt ~f cl =
match f cl with
| Some cl' ->
SimplM.return_new cl'
| None ->
SimplM.return_same cl
let simplify_cl = simplify_opt ~f:do_hte_hle
let propagated_hle_hte = simplify_opt ~f:do_propagated_simpl
let unit_htr = simplify_opt ~f:unit_simplify
let untrack_clause cl =
(match Util.Int_map.get (C.id cl) !cl_occs with
| Some premises ->
Term.Set.iter (fun premise ->
prems_ := PremiseIdx.update_leaf !prems_ premise (fun (tbl,_) ->
T.Tbl.filter_map_inplace (fun concl proofset ->
if CS.mem cl proofset then (
concls_ := ConclusionIdx.remove !concls_ concl premise;
None
) else Some proofset) tbl;
T.Tbl.length tbl != 0)) premises;
| _ -> ());
if Util.Int_map.mem (C.id cl) !cl_occs then (
Util.debugf ~section 3 "removed: @[%a@]." (fun k -> k C.pp cl);
decr tracked_cls;
);
cl_occs := Util.Int_map.remove (C.id cl) !cl_occs;
match get_unit_predicate cl with
| Some unit ->
units_ := UnitIdx.remove !units_ unit cl
| None -> ()
let initialize () =
let track_active () =
Signal.on_every Env.ProofState.ActiveSet.on_add_clause track_clause;
Signal.on_every Env.ProofState.ActiveSet.on_remove_clause untrack_clause
in
let track_passive () =
Signal.on_every Env.ProofState.PassiveSet.on_add_clause track_clause;
Signal.on_every Env.ProofState.PassiveSet.on_remove_clause untrack_clause
in
let track_all () =
Signal.on_every Env.ProofState.PassiveSet.on_add_clause track_clause;
Signal.on_every Env.ProofState.ActiveSet.on_remove_clause untrack_clause;
Signal.on_every Env.on_forward_simplified (fun (c, new_state) ->
match new_state with
| Some c' ->
if not (C.equal c c') then (
track_clause c'
)
| _ -> untrack_clause c )
in
let initialize_with_passive () =
assert (Iter.is_empty @@ E.get_active ());
Iter.iter track_clause (E.get_passive ());
Util.debugf ~section 3 "discovered implications:" CCFun.id;
PremiseIdx.iter !prems_ (fun premise (tbl,_) ->
Util.debugf ~section 3 "@[%a@] --> @[%a@]" (fun k -> k T.pp premise (Iter.pp_seq T.pp) (T.Tbl.keys tbl))
)
in
begin match Env.flex_get k_clauses_to_track with
| `Passive ->
initialize_with_passive ();
track_passive ()
| `Active ->
track_active ()
| `All ->
initialize_with_passive ();
track_all ()
end;
Signal.StopListening
let setup () =
if E.flex_get k_enabled then (
Signal.on Env.on_start initialize;
let add_simpl =
if Env.flex_get k_simpl_new
then Env.add_basic_simplify
else Env.add_active_simplify
in
add_simpl simplify_cl;
if Env.flex_get k_unit_propagated_hle then (add_simpl propagated_hle_hte);
if Env.flex_get k_unit_htr then (add_simpl unit_htr)
)
end
let max_depth_ = ref 3
let enabled_ = ref false
let simpl_new_ = ref false
let clauses_to_track_ = ref `Active
let max_self_impls_ = ref 1
let max_tracked_clauses = ref (-1)
let propagated_hle = ref true
let unit_htr_ = ref true
let hte_ = ref true
let hle_ = ref true
let track_eq_ = ref false
let insert_ordered_ = ref false
let extension =
let register env =
let module E = (val env : Env.S) in
let module HLT = Make(E) in
E.flex_add k_enabled !enabled_;
E.flex_add k_max_depth !max_depth_;
E.flex_add k_simpl_new !simpl_new_;
E.flex_add k_clauses_to_track !clauses_to_track_;
E.flex_add k_max_self_impls !max_self_impls_;
E.flex_add k_unit_propagated_hle !propagated_hle;
E.flex_add k_unit_htr !unit_htr_;
E.flex_add k_max_tracked_clauses !max_tracked_clauses;
E.flex_add k_track_eq !track_eq_;
E.flex_add k_hle !hle_;
E.flex_add k_hte !hte_;
E.flex_add k_insert_only_ordered !insert_ordered_;
HLT.setup ()
in
{ Extensions.default with
Extensions.name = "hidden literal elimination";
prio = 100;
env_actions=[register]
}
let () =
Options.add_opts [
"--hidden-lt-elim", Arg.Bool ((:=) enabled_), " enable/disable hidden literal and tautology elimination";
"--hidden-lt-elim-max-tracked", Arg.Int ((:=) max_tracked_clauses), " negative value for disabling the limit";
"--hidden-lt-elim-hle", Arg.Bool ((:=) hle_), " enable/disable hidden literal elimination (hidden-lt-elim must be on)";
"--hidden-lt-elim-hte", Arg.Bool ((:=) hte_), " enable/disable hidden literal tautology elimination (hidden-lt-elim must be on)";
"--hidden-lt-max-depth", Arg.Set_int max_depth_, " max depth of binary implication graph precomputation";
"--hidden-lt-simplify-new", Arg.Bool ((:=) simpl_new_), " apply HLTe also when moving a clause from fresh to passive";
"--hidden-lt-track-eq", Arg.Bool ((:=) track_eq_), " enable/disable tracking and simplifying equality literals";
"--hidden-lt-clauses-to-track", Arg.Symbol(["all";"passive";"active"],
(function
| "all" ->
clauses_to_track_ := `All;
| "passive" ->
clauses_to_track_ := `Passive;
| "active" ->
clauses_to_track_ := `Active;
| _ -> ())),
" what clauses to use for simplification";
"--hidden-lt-max-self-implications", Arg.Int ((:=) max_self_impls_),
" how many times do we loop implications of the kind p(X) -> p(f(X)) ";
"--hidden-lt-propagated-hle", Arg.Bool ((:=) propagated_hle),
" do unit-triggered removal of literals ";
"--hidden-lt-unit-htr", Arg.Bool ((:=) unit_htr_),
" do unit hidden tautology removal ";
"--hidden-lt-insert-ordered", Arg.Bool ((:=) insert_ordered_),
" for clauses of the form l|r where l > r then insert only ~l -> r ";
];
Extensions.register extension